The Confocal Scanning Microscope Facility within the Department of Biology will serve as shared facility, oriented primarily to the needs of the developmental biology subgroup. While recent advances in light microscopy have opened many new avenues of research, the new instruments are expensive; the goal of the Facility will be to achieve efficient use, providing maximum access to these instruments for the participating scientists. Funds are requested here for a new scanning confocal fluorescence microscope and for an optical memory disc recorder. The Facility will also house the Departmental Zeiss Axiomat, which is equipped for microinjection. The Facility will be supervised by the P.I., Dr. Sarah C.R. Elgin, with the assistance of a skilled technician, Michael Veith, and will be housed in new space congruent with the laboratory space of the developmental biology subgroup. Computer interfacing and software developmental will be directed by Dr. James McNally, who holds a primary appointment in Biomedical Computing. The major research projects which will make use of the facility are the following: 1) Analysis of the role of chromatin structure in the control of gene expression (S.C.R. Elgin). The microscope will be used to analyze the distribution of certain chromosomal proteins in the polytene chromosomes and to determine the timing of association of certain chromosomal proteins in the polytene chromosomes and to determine the timing of association of certain chromosomal proteins with nuclei in the early embryo of Drosophila. 2) Analysis of the cell division apparatus in Volvox (D.L. Kirk). These studies are aimed at understanding the mechanism of asymmetric division that differentiates the large immortal germ cells from the small mortal somatic cells. 3) Analysis of morphological regulation in Drosophila (I.M. Duncan). Detailed studies are planned to establish the precise localization of fushi tarazu and bithorax protein products in embryo whole mounts by immunofluorescence. 4) Analysis of the patterning mechanism of Polysphondylium pallidum (J.G. McNally). The distribution of structural proteins, including elements of the cytoskeleton, will be analyzed to determine whether cell movement is a response to or an actual component of the patterning machine. All of these studies will provide basic information of mechanisms of growth and development.